1. Field of the Invention
The present invention relates to a hollow golf club head.
2. Description of the Related Art
A hollow golf club head has been known. The hollow structure increases a head volume and a moment of inertia. A so-called wood type golf club head is usually hollow.
The volume of a hollow part is increased and the thickness of the head is thinned with the increase in size of the head. When the hollow part is great, a hitting sound is loud. Since the vibration of the head is great when the thickness is thin, the hitting sound is loud. The head increased in size causes a loud hitting sound.
Golf club heads for obtaining a good hitting sound have been disclosed. As the inventions considering a hitting sound, Japanese Unexamined Patent Application Publication No. 2002-186691, Japanese Unexamined Patent Application Publication No. 10-33723, U.S. Pat. No. 7,056,228, and U.S. Pat. No. 7,247,103 are disclosed.